The snuff video has become the new calling card of ideological conflict in the 21st century. This sadistic defiance of every civilised norm — the celebratory, often stylised depiction of ritual murder — was pioneered by al-Qa’ida. It’s now been adopted with depraved glee by al-Qa’ida’s ultra-violent offspring, the Islamic State of Iraq and al-Sham.

ISIS is not ashamed of its violence. It rejoices in murder. Death is its purpose. As it drove through the Iraqi cities of Tikrit and Mosul it captured hundreds of Iraqi soldiers. The reports vary but it seems that when it captured Shi’ite Iraqi soldiers it executed them summarily. But, according to the videos it has posted on Twitter, it also took many to shallow mass graves and shot them for the camera.

Terrorism is always partly for the camera.

Prime Minister Tony Abbott says the situation in Iraq is “a ­security disaster for the Middle East, but also for the wider world”.

He says the triumph of ISIS in some parts of Iraq is a “humanitarian disaster”, and that ISIS is “carrying out extraordinary brutality towards surrendering Iraqi soldiers and policemen”, and that the areas of Iraq and Syria that ISIS controls are in danger of becoming “a terrorist state”.

Tony Blair called for direct military intervention in the shape of airstrikes.

US Secretary of State John Kerry said the US would be happy to co-operate with Iran if necessary to stop ISIS.

President Barack Obama ruled out sending combat troops but did dispatch 275 US servicemen to protect the American embassy in Baghdad.

Where does all this come from and what does it all mean?

The triumph, for the moment, of the Sunni terrorist ISIS is both a critical development in the Middle East, and a sign of the unravelling of the liberal international order.

That liberal order, which we thought was born at the end of the Cold War, but which really has its origins at the end of World War II, holds that big, powerful states won’t seek to take territory from other states. It also holds that globalisation and trade makes everybody so interdependent that large scale war is no longer attractive or profitable. It stresses international co-operation on cross border ­issues under the auspices of the United Nations and regional and functional multilateral agencies. It talked even of an international rule of law backed up by such institutions as the International Court of Justice and the like.

But now this international order, in so far as it ever existed at all, is breaking down at all levels. The ISIS success is one key manifestation of this, but the breakdown is occurring much more widely.

The international order is being challenged at the bottom by terrorists who are eroding state sovereignty across the Middle East, North Africa and South Asia. Al-Qa’ida has had huge success during the war on terror in recruiting thousands of young men in these regions to its religious and political vision.

The liberal international order is also being challenged above the level of the state, as it were, by cyber warfare which is destroying the confidentiality and the security of the intellectual property of Western nations.

And it is being challenged at the level of international relations by Russia and China.

The actions of Russia in invading Crimea and sponsoring violent rebellion in eastern Ukraine have not been met with any decisive response from the West. These ­actions have succeeded.

Russia’s economy has suffered as a result of capital flight and some loss of confidence. The West has enacted some sanctions. But these are miles from being crippling. Germany is not going to give up Russian energy or trade. France is not going to reverse military sales. Britain will not root Russia out of its financial system, or ­indeed its housing market. Old fashioned territorial conquest works after all.

China’s actions are on a much smaller scale, but they involve ­occupying disputed reefs and ­islands in the South China Sea, and declaring an Air Defence Identification Zone over islands disputed with Japan in the East China Sea and then enforcing those actions. No Southeast Asian nation can challenge Chinese control of a disputed island, and really only the US and Japanese air forces are prepared to flout the ADIZ. Possession is 10 10ths of the law. Again, territorial conquest works. US disapproval, much less international opinion, is not decisive.

But terrorism is also exploding the liberal international order, ­especially in the Middle East.

ISIS has a specific and unique history which contributes to its extravagant brutality and bloodthirstiness. But it is still representative of large social movements across North Africa, the Middle East and South Asia.

The West has not won the war on terror, as Obama claimed after the death of Osama bin Laden. He made a self-congratulatory speech then saying terrorism was no longer a central concern of US foreign policy. This triumph was as short-lived as George W. Bush’s “mission ­accomplished” moment. In Obama’s recent West Point speech, terrorism was back to centre stage.

The analysis of terrorism has been blighted in the West by stovepipe thinking. The analysts of terrorism are pretty good but don’t tend to relate it to traditional geo-strategic concerns. Those analysts more comfortable with geo-strategic issues always want to dismiss terrorism as no more important than a bad storm, or essentially a policing problem.

The real challenge of terrorism has eluded both schools of analysts in two ways.

First, terrorism is an enormous and potentially existential threat, which consumes a huge amount of resources. But it doesn’t remove the pre-existing geo-strategic challenges posed by the likes of Russia and China.

Instead, the real complexity of terrorism lies in the way it interacts with traditional geo-strategic challenges and complicates and magnifies them.

The momentum for the US-led invasion of Iraq in 2003 came from the 9/11 terror attacks. Washington never suggested Iraq was behind those attacks but it was the danger of Saddam Hussein possessing weapons of mass destruction and supporting terrorists that motivated Washington.

Now, however, Iraq is ungovernable.

Nonetheless, we should not be too simple in our attribution of cause and effect. The US did not invade Syria and it is equally ungovernable, perhaps more so.

For years the US was accused by critics around the world of supporting dictators in the Middle East. It took one dictator out, in Iraq, and withdrew support from another dictator, in Egypt, and the result was chaos. In Iraq, for the moment, the terrorists are in the ascendant. In Syria the dictator and the terrorists are fighting out a bloody draw. In Egypt the military dictatorship has come back. Meanwhile for the last year the US Secretary of State, John Kerry, has been diverting himself by focusing on the Israeli/Palestinian dispute, perhaps the least urgent matter on the entire Middle East agenda.

So this seems to be the policy choice for the West in the Middle East — either support dictatorship or empower terrorists.

In a recent interview British Foreign Secretary William Hague told me that he believed there was a need for Western foreign policy in general to re-establish its credibility.

Yesterday I spoke at some length to Karl Eikenberry, a former general in the US Army who served in Afghanistan as a soldier and then later as US ambassador in Kabul.

He warned of the dangers of second and third order unanticipated consequences of any military action in Iraq.

“What’s the compelling US interest?” he asked.

“We cannot allow a large part of that region to fall into terrorist hands. We also have other interests, energy supply, the security of Israel, the reputational consequences should Iraq continue in a downward spiral.”

He said that the Obama administration was correct to talk to the Iraqi government of Nuri al-Maliki and make clear that any support would depend on Baghdad running a more inclusive political strategy, one that catered for Sunni and Kurdish interests as well as the interests of the majority Shia population.

Eikenberry does not mince words on the overall wisdom of the US involvement in Iraq. “I would characterise the decision to attack Iraq as the most catastrophic foreign policy mistake in the history of the US.

“Look at the Middle East today. Look at the cost. We had 4500 (American) lives lost. The fiscal cost to the US was probably $US1 trillion. Then if you look at the added healthcare costs for personnel out to about 2050 it’s probably in the hundreds of billions of dollars.

“Then look at the Iraqi costs — hundreds of thousands of lives lost. And I’m not at all sure Iraq is a better place today no matter how bad it was under Saddam Hussein.

“It just did not come out as it was hoped for. It’s been a disaster.”

Eikenberry, who is visiting Australia for the Alliance 21 Conference sponsored by the US Studies Centre at Sydney University, does also stress, however, that he believes the US political leadership operated in good faith, both in their intentions for their intervention and in their beliefs about Iraq’s possession of weapons of mass destruction.

Eikenberry’s claim is tough minded, but also contestable. ISIS, in its former incarnation of al-Qa’ida in Iraq, had been substantially defeated by the time the American troops left Iraq. There is a reasonable criticism of Obama that he should have worked harder for an agreement to keep a smaller US troop presence in Iraq for longer. But as others have pointed out, the people who made Iraq ungovernable over the past few years are primarily the Iraqi government of Maliki.

His government dismissed the prominent Shi’ites from virtually all significant positions in the state apparatus. He failed to maintain a good relationship with the Kurds, who now look as though they have their best chance ever to establish a fully independent state. Maliki’s government did not integrate Sunnis into the army as he promised. He did not maintain a solid relationship with the Sunni tribal leaders who had fought al-Qa’ida in the past.

All this made a Sunni revolt more likely, and explains why some Sunnis who don’t share all of ISIS’s murderous ideology have nonetheless allied with ISIS.

It is impossible now to believe that Syria and Iraq will ever be reconstituted as the states that they were. The map of the Middle East is being redrawn, and it is covered in blood.

The liberal international order, fraying at the edges and collapsing in the middle, has nothing much, it seems, to offer this situation.